Dali, just make sure the receiver knows that there aren't any rear speakers connected, so that these channels will be rerouted to your side surrounds.
Oh yeah, make sure that you connect the side surrounds to the correct terminals, and not to the rear speaker terminals, hehe. If you made that mistake, compounded with the mistake of not letting the receiver know rears are to be disabled, you would be missing out on a lot of surround info meant for the sides, but perhaps not know it . . .